Buggy code:
public class KeyManager { private static final String KEY_SEQUENCE_SEPARATOR = ",<seq2seq4repair_space>" ; private static final String KEY_STROKE_SEPARATOR = "<seq2seq4repair_space>" ; private static final String LOCALE_SEPARATOR = "_" ; private static final String OR_SEPARATOR = "||" ; private static KeyManager instance ; public static KeyManager getInstance ( ) { } public static List parseKeySequences ( String keys ) { } private static Path pathForConfiguration ( String id , Map configurationMap ) { } private static Path pathForScope ( String id , Map scopeMap ) { } private static Path pathForLocale ( String locale ) { } private static Path pathForPlatform ( String platform ) { } private static Path systemLocale ( ) { } private static Path systemPlatform ( ) { } private static SortedMap buildConfigurationMap ( SortedMap registryConfigurationMap ) { } private static SortedMap buildScopeMap ( Map registryScopeMap ) { } private static List buildBindings ( List definitions , SortedMap configurationMap , SortedMap scopeMap ) { } private static List readDefinitions ( IMemento memento ) throws IllegalArgumentException { } private static void writeDefinitions ( IMemento memento , List definitions ) throws IllegalArgumentException { } private SortedMap registryConfigurationMap ; private SortedMap registryScopeMap ; private List registryDefinitions ; private SortedMap preferenceConfigurationMap ; private SortedMap preferenceScopeMap ; private List preferenceDefinitions ; private SortedMap unifiedConfigurationMap ; private SortedMap unifiedScopeMap ; private List unifiedDefinitions ; private SortedMap configurationMap ; private SortedMap scopeMap ; private List bindings ; private String configuration ; private String [ ] scopes = new String [ ] { null } ; private KeySequence mode = KeySequence . create ( ) ; private boolean valid ; private KeyMachine keyMachine ; private KeyManager ( ) { } public SortedMap getRegistryConfigurationMap ( ) { } public SortedMap getRegistryScopeMap ( ) { } public List getRegistryDefinitions ( ) { } public void loadRegistry ( ) { } public List getPreferenceDefinitions ( ) { } public void loadPreferences ( ) { preferenceConfigurationMap = Collections . unmodifiableSortedMap ( new TreeMap ( ) ) ; preferenceScopeMap = Collections . unmodifiableSortedMap ( new TreeMap ( ) ) ; preferenceDefinitions = Collections . EMPTY_LIST ; IPreferenceStore preferenceStore = WorkbenchPlugin . getDefault ( ) . getPreferenceStore ( ) ; String preferenceString = preferenceStore . getString ( "org.eclipse.ui.keys" ) ; <START_BUG> if ( preferenceString != null ) { <END_BUG> StringReader stringReader = new StringReader ( preferenceString ) ; try { XMLMemento xmlMemento = XMLMemento . createReadRoot ( stringReader ) ; IMemento memento = xmlMemento . getChild ( "definitions" ) ; if ( memento != null ) preferenceDefinitions = Collections . unmodifiableList ( KeyManager . readDefinitions ( memento ) ) ; } catch ( WorkbenchException eWorkbench ) { } } invalidate ( ) ; } public String getConfiguration ( ) { } public void setConfiguration ( String configuration ) { } public String [ ] getScopes ( ) { } public void setScopes ( String [ ] scopes ) throws IllegalArgumentException { } public KeySequence getMode ( ) { } public void setMode ( KeySequence mode ) throws IllegalArgumentException { } private void invalidate ( ) { } public KeyMachine getKeyMachine ( ) { } public String getTextForAction ( String action ) throws IllegalArgumentException { } public String getTextForKeySequence ( KeySequence keySequence ) throws IllegalArgumentException { } }

Fix:
if ( ( preferenceString != null ) && ( ( preferenceString . length ( ) ) != 0 ) ) {